THE PHYSICAL ACTION OF LIME 
ON CLAY SOILS 



A THESIS 

PRESENTED TO THE FACULTY OF THE GRADUATE SCHOOL 
OF CORNELL UNIVERSITY FOR THE DEGREE OF 

DOCTOR OF PHILOSOPHY 



BY 
ROBERT MIFFLIN SNYDER 



December, 292 7 



THE PHYSICAL ACTION OF LIME 
ON CLAY SOILS 



A THESIS 

PRESENTED TO THE FACULTY OF THE GRADUATE SCHOOL 
OF CORNELL UNIVERSITY FOR THE DEGREE OF 

DOCTOR OF PHILOSOPHY 



BY 

ROBERT MIFFLIN SNYDER 
•I 



December, 1917 



CsrvOT 



Sk-f 3 

mi? 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

The recent investigations in the field of soil acidity have raised anew 
the question of the physical action of lime on the soil. A number of 
physical investigations have been conducted in the past, but the recent 
progress in certain auxiliary subjects, as colloid chemistry, has tended 
to depreciate the value of much of this work, and bring new problems 
to the front. The question may therefore be properly considered again : 
What is the specific effect of each form of lime on the soil, and how great 
is that effect? 

Our problem resolves itself into two parts: First, the selection of 
desirable methods, and second, their application. Let us first review the 
procedures available for the study of the colloidal characteristics of the 
soil, and determine wherein their merits and deficiencies lie. The vari- 
ous methods may be classified under eight distinct headings, as follows: 

Methods for Estimating Soil Colloidality 

Flocculation in solution. 

1. The suspension method. 
Solubility of colloidal material. 

2. Fraps Ammonia Method. 

3. Van Bemmelen Acid Method. 
I. Endosmometer method. 

Heat Liberation on Wetting. 

r>. Pouillet-Mitscherlich Method. 
Capillarity and Retentive Power. 

6. Hilgard Total Retentive Cup Method. 

7. Briggs and McLane Moisture Equivalent Method. 

8. Capillary Rise of Water* 

9. Percolation of Water. 

10. Atterberg Plastieity Method. 
Adsorption. 

11. Hygroscopic Water. 

12. Dye Adsorption. 

13. Selective Adsorption of ions. 

14. Endell Histological Method. 
Volume Change. 

15. Expansion Method. 

ACKNOWLEDGMENT 

Tlir writer rakes pleasure in acknowledging his obligations to Professors T. L. Lyuii, W. 1>. 
Bancroft. 'I'. R. Briggs, and II. O. Biickman for helpful criticisms awl suggestions lie is 
particularly Indebted to Professor J. A. r,i/,/<U, under the immediate di ection of whom the 
work was conducted. 



4 THE PHYSICAL ACTION OP LIME ON CLAY SOILS 

Penetrability. 

16. Penetration Method (Laboratory). 

17. Dynamometer Method (Field). 
Oxidation. 

18. The Oxidation Method. 

1. The Suspension Method has been used more extensively than any 
other. It consists essentially in making a suspension of the material in 
the particular solution to be tested, and observing the time required for 
precipitation. For a number of decades the suspension method was the 
only means by which the effect of ions on the stability of colloidal ma- 
terial could be determined. In the hands of Schulze, Bams, Picton and 
Linder, Bodlander, and Hardy, it was of immense assistance in the form- 
ulation of the fundamentals of colloid chemistry. The specific action of 
various salts, and the valence and mass relations, have been popular sub- 
jects for study. The most recent work with clay suspensions has been 
performed by Masoni, and by Wolkoff. 

Valuable as the suspension procedure has been in the preliminary 
studies, the question nevertheless arises whether it should be considered 
a legitimate method for correctly estimating the physical effects of salts 
on soils. The writer is of the opinion that the precipitation of a sol by 
an electrolyte is of little value in gauging the action of the same salt 
applied to a soil under natural conditions. In a suspension the forces 
inhibiting the neutralization of charges are very small, while in a heavy 
soil the internal friction prevents the formation of the large floccules 
characteristic of the suspension. Probably in many heavy clays the posi- 
tively changed colloidal iron remains indefinitely in approximate con- 
tiguity to the negative silicia without neutralization taking place. 

A somewhat similar view regarding the inapplicability of the suspen- 
sion method is held by Free. He thinks that in the soil, the tension at 
the liquid-vapor surface may be the determining factor in precipitation. 

2. Fraps has studied the ammonia soluble inorganic soil colloids. He 
does not propose his method as a means by which the entire colloidal 
content of the soil may be measured. 

3. The Van Remmelen Method for the estimation of soil colloids con- 
sists in the determination of the material made soluble on prolonged 
digestion with hydrochloric and sulfuric acids. In the hands of Blanck 
and Dobrescu, and Vander Leeden and Schneider, the Van Bemmelen 
procedure has not yielded significant results. A serious criticism of the 
method lies in the fact that crystalloidal as well as colloidal matter may 
be rendered soluble. 

4. The Endosmometer Method has been used by Konig, Hasenbaumer 
and Hassler for the determination of the absorbed ions in the soil. The 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 5 

amount of salts released by the current bears only a very indirect rela- 
tion to the amount of colloidal material. 

5. The "Ponillet Effect" is another means by which the estimation 
of internal surface has heen attempted. This method is named after C. 
Pouillet, who as far back as 1823 observed that finely divided substances 
released heat on wetting. Mitscherlich (1898) was the first to attempt 
the estimation of the internal surface of soils by the use of this phe- 
nomenon. Several other investigators have since then attempted similar 
studies. The fact that heat release in soils may be associated with a 
number of factors renders the Pouillet effect of doubtful value. 

fi. The total retentive power of the soil for water has long been used 
as a standard measurement. The early investigators usually allowed 
water to rise by capillarity in a cylinder filled with the soil, and then 
determined the final percentage present. Hilgard modified the procedure 
by using a short column of standard length, but the method still remains 
rather inaccurate. 

The investigations of Trentler, Wollny, Blanck, and Engels indicate 
that calcium oxide increases the total retentive power of the soil. All 
these men, however, used excessive applications. The probable error in 
the case of Timer's work is too high to permit the drawing of conclusions. 
Frear thinks that liming has no effect on the total retentive power. The 
writer is calling attention in each case to the instances in which limed 
soils have been used, for there is no better criterion as to the accuracy 
of a physical method, than its sensitivity to small amounts of lime. 

7. The Moisture Equivalent Method of Briggs and McLane suggests 
itself as a possible means for estimating internal surface. Unfortunately. 
the probable error is so high as to probably preclude the measurement 
of very small lime applications. Sharp, of the California Station, is using 
this method at the present time in his alkali investigations. 

8. The capillary rise of water in soil columns has been used by 
several investigators as a method for estimating soil colloidality. The 
usual procedure has been to place the lower end of a column of dry soil 
in contact with water, and record the speed and total height of ascent. 
Meve*\ Krawkow, Gross. Blanch, and Engels have performed capillary 
experiments with lime treated soils. The data, considered as a whole, 
is inconclusive. Undoubtedly, internal surface is a factor in capillary 
rise, but the additional factors of surface tension and degree of compac- 
tion are exceedingly difficult to control. 

9. The speed of percolation of water through soils has frequently been 
used as a measure of soil structure. Studies have been conducted by 
Vogel, Ebermeyer, Buhler, Blanck, Thaer, and Engels on the influence 
of lime on percolation. All agree that lime increases the ease with which 
water passes downward. For comparative purposes it is necessary to 
obtain a large volume of percolate, and this results in the removal of 



6 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

salts from the sample. An objection to this procedure rests in the fact 
that the colloidal condition, the factor which we are measuring, depends 
on the salt content. A decrease in the amount of adsorbed salts results in 
a deflocculation of the soils. Both Mayer and Van Bemmelen noted at an 
early date that percolation decreased on prolonged leaching, and the same 
thing has been more recently noted by Hall, and by Sharp. 

10. The Atterberg Plasticity Method has been proposed solely as a 
means of evaluating clays. It has never been applied to the estimation 
of internal surface. According to Kinnison, the Atterberg plasticity 
figure depends on too many factors to be of value. 

11. The term "hygroscopic moisture" has usually been taken to mean 
the amount of Water that a soil will absorb in order that its internal 
surface be covered with a film one molecule in thickness. However, there 
is reason to believe that the thickness of the film is greater than that 
stipulated by the definition. Furthermore, the slowness in reaching 
equilibrium, and the great effect of temperature on the final result, indi- 
cate that much of the water is present in the form of capillary water 
located in the interstices of the soil particles. It is more correct to speak 
of the phenomenon as "hygro-interstitial moisture," connoting thereby its 
true nature. 

The early workers tested out the absorptive power of soils for various 
vapors and gases. All these investigations resulted in the selection of 
water vapor as best suited for the purposes in hand. The hygro-inter- 
stitial investigations have been conducted according to two general types 
of procedure : 

1. The first involves the constant passage of water vapor over or 
through a soil until equilibrium is reached. 

2. The second requires the placing of the sample in an atmosphere 
whose degree of saturation is controlled, the moisture being conveyed to 
or- from the soil by diffusion. 

The classical investigations of Ammon and of von Dob'eneck belong to 
the first type. They conducted the saturated vapor through a U-tube or 
some other suitable vessel containing the soil, until equilibrium had been 
reached. Both men were concerned with the adsorptive power of the 
various soil constituents, and so carefully was their work conducted, that 
it remains today our most valuable contribution to the subject. 

One of the difficulties with the procedure was the frequency with which 
an abnormal condensation of water vapor occurred on the interior of the 
containing vessel. This led to the practice of reducing the degree of 
saturation of the water vapor. Heiden, for instance, emploved a vapor 
approximately seventy-five per cent saturated, but he could not obtain 
valuable results. Owing to the difficulties of manipulation the subject 
wa« abandoned, and during the nineties no work was done on any phases 
of the question. 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 7 

In 1903, Rodewald and Mitscherlich proposed a method corresponding 
to the second type of procedure outlined above. The soil sample, pre- 
viously dried over phosphorus pentoxide, was placed in a container over 
ten per cent sulfuric acid until equilibrium was attained. The function 
of the sulfuric acid was to control the degree of humidity and prevent 
condensation. This method has been used by a large number of investi- 
gators. Engels, Thaer, and Ozermack have found that lime, particularly 
calcium oxide, decreases the hygro-interstitial moisture. The amounts of 
lime which they used, however, were excessive. 

Comparisons of the Rodenwald-Mitscherlish method with the other 
means of measuring internal surface have been attempted by Tadokoro, 
and Stremme and Aarnio. They find a good general agreement between 
the different methods. It should be pointed out in this connection, how- 
ever, that a good general correlation is to be expected in comparing soils 
whose percentages of clay vary widely. 

The possibility of the desiccation over phosphorus pentoxide having an 
influence on the colloidal material has been pointed out by Ehrenberg 
and Pick. They suggest that moist soil be placed in the desiccator or 
humidor and allowed to remain until equilibrium is obtained. 

There are two main objections to the Rodewald-Mitscherlich method and 
its modifications : 

1. Too much time is consumed in waiting for equilibrium to be reached 
in any particular case. 

2. There is a high probable error in the method, due probably to the 
fact that diffusion permits only an approximation of true equilibrium 
conditions. 

Blanck ran soils according to the Ehren berg-Pick modification in one 
instance for a period considerably exceeding one hundred days, at the 
end of which time equilibrium had not been reached. 

12. The Dye Adsorption Method constitutes one of the standard means 
for determining the internal surface of soils. 

Undoubtedly, there exists in the soil a great variety of colloidal sub- 
stances varying in both chemical and physical condition. Four forms, 
namely, iron, aluminum, humus, and silica, have been generally recog- 
nized. This classification is of the crudest sort, and undoubtedly comes 
far from conveying an adequate conception of the variety of colloidal 
materials present. When we recall that the weathering processes usually 
increase the amount of colloidal matter, we might expect to find about 
as many colloids present in the soils as original rock sources. Rogers has 
made a review of the mineral kingdom, and finds a great number of min- 
erals to be colloidal in nature. Many of them, we have reason to believe, 
exist in the soil, as, for instance, allophane, elemental carbon, opal, hema- 
tite, and limonite. Soils of volcanic origin probably contain pyrolusite 
and rutile. 



8 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

The use of dyes in the identification of minerals has been undertaken 
by Pelet and Grand, Hundeshagen, Dittler and Cornu. Certain dyes are 
used which will be adsorbed by specific substances, and thus an attempt 
is made to identify the materials present. Unfortunately, it is not always 
possible to differentiate between the colloidal and crystalloidal matter. 
Furthermore, it is possible that colloids of approximately the same chem- 
ical composition may vary in their adsorptive powers for dyes. Such 
factors as the amount of water of hydration may quantitatively influence 
the results. Rohland and von Possanner find that talc and kaolin vary 
widely among themselves as to their adsorptive properties, and according 
to Bancroft, the nature of hydrous ferric oxide varies with the method 
of preparation. 

It is possible that in the soil we have processes which tend to simplify 
the nature of the colloidal material. Lacroix, in a study of the decompo- 
sition products of the aluminum silicate rocks, concluded that the end 
product was hydrous aluminum oxide. Rohland holds the same view. In 
fact, it seems necessary to assume an hydrolysis of the silicates in order to 
explain the beneficial action following the application of calcium silicates 
to the soil. Whether hydrolysis takes place or not, the probabilities, 
nevertheless, are that in most soils we have a vast series of colloidal 
materials present, each varying somewhat in its qualitative and quanti- 
tative adsorptive power. It is, therefore, apparent that any dyestuff is 
only very roughly specific with regard to its adsorbent. 

In view of the insolved nature of the subject, there has existed in the 
literature the greatest confusion with regard to the use of dyes on soils 
and the interpretation of the results obtained. However, the fact that 
certain dyes are adsorbed only by certain colloids when prepared in the 
pure state, permits our obtaining some idea as to the nature of the 
adsorbing material in the field. The weakness of the method consists 
in the fact that, owing to the variation in the properties of the colloidal 
matter, our evidence is circumstantial at best. 

Before proceeding further, it seems necessary to discuss certain factors 
influencing dyestuff adsorption, and indicate their relation to soils work. 

1. Nature of the dye. The opinion lias existed in the soils literature 
that all dyes were equally valuable, as long as they were adsorbed. No 
idea could be more erroneons. Lyollema in 1905 found that certain dyes 
were specific for certain materials. The specificity of dyes has been 
worked out further by Rohland, and Beaumont; subject, of course, to 
the limitations reviewed in the preceding pages. We find that the azo 
dyes are adsorbed practically not at all. Rohland has tried to correlate 
this peculiarity of the azo dyes with certain molecular configurations. 
He finds safranine and indigo (the leuco indigo white?) to be specific 
for humus. Beaumont thinks diamine sky blue is adsorbed by colloidal 
aluminum. The tri-phenyl methane dyes are taken up by both humus and 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 9 

silica. Methylene blue, while adsorbed slightly by humus and aluminum, 
is taken up in such enormous amounts by silica, that it may be rightly 
considered specific for the latter. The writer has found eosin to be 
admirably adapted for aluminum. No dye has yet been found which is 
satisfactory for hydrous ferric oxide. Summarizing, then, we have the 
following as the best suited for soils adsorption work. 

Hydrous ferric oxide, — no dye. 

Hydrous aluminum oxide. — eosin and diamine sky blue. 

Humus, — safranine. 

Silica,— methylene blue. 

2. The concentration of the dye employed should be small. Within 
narrow limits, adsorption is a linear function of the concentration. The 
curve obtained by plotting the amount adsorbed against concentration 
ceases to be linear, however, on increasing the concentration of the dye 
solution. Further, the stability of the sol may be affected if the dye is 
too concentrated. 

3. The dye should be stable irrespective of the reaction of the bath. 
All dyes which in alkaline solution are changed into the dye-base or 
leuco-base are unsuited for soils which give an alkaline filtrate on wash- 
ing. Inasmuch as the great majority of soils render an aqueous solution 
alkaline, all colors exhibiting the above characteristics, as the tri-phenyl 
methane dyes, for instance, should be discarded. Unfortunately, this 
includes the greater portion of the colors used in the past, as crystal, 
methyl, and gentian violet, aniline blue, aniline green, aniline red, methyl 
green, malachite green, etc. Changing the reaction of the solution after 
adsorption is usually not sufficient to restore the color to the dye, since 
alkalinity may reduce the dye base to the leuco form. Oryng, and Adams 
and Kosenstein have called attention to the difficulties inherent with the 
triphenyl methane dyes. It is not surprising that Gedroits, using crystal 
and methyl violet, found no relation between colloidality and adsorption. 

Another potential source of error lies in the fact that alkali may unite 
with the dye and form a lake. This is what happens in the case of alizar- 
ine, one of the dyes recommended by Ljollema. Tadokoro, in selecting a 
color for his work, chose eosin, because it was stable in acid or alkaline, 
but he overlooked the fact that eosin is specific for hydrous aluminum 
oxide. We probably obtain no eosinic lake formation in the case of 
adsorption by soils. Too much care cannot be taken that the dye is 
stable under all conditions. 

4. The reaction of the solution should not affect the adsorption equili- 
brium. In the textile industries the amount of dye taken up in any 
particular case is largely determined by the degree of reaction of the 
bath. The subject is summarized by Bancroft as follows : 

The following holds for an acid dye : 



10 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

a. The dye is taken up most readily in an acid solution but may be 
taken up in a neutral or alkaline solution. 

b. A readily adsorbed anion decreases the amount of dye taken up. 

c. A readily adsorbed cation increases the amount of dye taken up. 
The effect of the reaction on dye adsorption has been extensively 

studied by Bancroft, and by Pelet-Jolivet and his co-workers. If the 
amount of salt in a sample of soil is large, the final equilibrium may be 
affected. In order to use the dye method as a measure of internal sur- 
face, we must satisfy ourselves by preliminary experimentation that the 
salt is present in too small an amount to influence the degree of adsorp- 
tion. It is readily apparent that we should use small charges of soil, 
particularly, if fertilizers have been added, for the amount of salt per 
unit concentration of dye increases directly with the amount of soil 
used. Kuprecht and Morse in their ammonium sulfate studies, found 
that the amount of dye taken up by the soil was increased after fertilizer 
treatment. We have no means of knowing from their work, however, 
whether the increase was due to the influence of the ammonium sulfate 
on internal surface, or whether it was the result of the changed reaction 
of the bath. The effect of the added material on the adsorption equili- 
brium has been in the past entirely overlooked in soils work. 

5. The protective action of organic matter on colloidal material has 
been recognized by a number of investigators. In running experiments 
on mineral colloids it is desirable to use soils as free from organic matter 
as possible. 

13. Selective adsorption has been used by many investigators as a 
means of estimating internal surface. Heiden, Parker, and Konig. 
Hasenbaumer, and Hassler are only a few of those who have taken the 
adsorptive power of the soil for potassium as a measure of the internal 
surface involved. The results lose their significance, however, when we 
recall that the soil contains a number of different kinds of colloidal 
material, each varying in its specificity with regard to adsorption. Thus. 
Thaer finds that the potassium ion is not adsorbed by colloidal humus, 
and Lokolovskii observes the same thing for the ammonium radical. 
Daikuhara believes that the adsorption of the potassium ion is character- 
istic of the colloidal iron and aluminum. The possibility of interchange 
of bases tends to further confuse the phenomenon. It is, therefore, not 
surprising that some workers, as Tadokoro, have failed to establish an 
agreement in the results from selective adsorption and some of our other 
more valuable methods. 

14. The Histological Method for the determination of colloids in clays 
was proposed by Endell. The dry clay is boiled in Canada balsam, and 
after cooling and hardening it is cut into small sections and colored with 
fuchsin. This method has been discussed by Cornu. Owing to the sim- 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 11 

plicity of certain other procedures, the histological method has never 
come into general use. 

15. Expansion methods are nearly as old as soil physics itself. In 
1838, Schubler began Avork on the subject, and his investigations have 
been continued by Haberlandt, von Schwarz, Puchner, and Wollny. The 
lime studies of Thaer and Engels resulted in the conclusion that there 
was a slight increase in volume on liming. In all the above cases the 
soils were allowed to come to dryness before making final measurements. 
Tempany (1917) finds that in drying down, internal friction between 
the soil particles becomes very great. This raises the question whether 
measurements after drying are particularly significant. Brown and 
Montgomery, in a study of the dehydration of clays, finds that shrinkage 
is no criterion of plasticity. Furthermore, it appears just as objection- 
able to make measurements from a dry to a moist condition, as vice versa. 
R. O. E. Davis cites data from Wollny in which the latter found that a 
dry soil moistened with water expanded six times as much as the same 
soil moistened with calcium hydrate solution! 

Wolff, and more recently Tadokoro, have studied the swelling exhibited 
by soils after being immersed in various reagents. This work is open 
not only to the objections already mentioned, but is also subject to the 
further criticism that swelling may be specific for the reagent employed. 
If expansion readings are made at a constant moisture content, we 
largely eliminate imbibitional factors, and may more correctly attribute 
differences to changes in soil structure. 

10. The cohesion method for the investigation of soil properties was 
first used by Schubler, who added a gradually increasing weight to a 
scale pan suspended from the middle of the dry brickette to be tested. 
This procedure has been used by Fippin in his investigation of the effect 
of lime on granulation. The Schubler method has been modified by 
Puchner, who suspends the scale pan above the knife edge entering the 
soil. The Atterberg procedure is essentially the same as that of Puchner, 
except that the scale pan is supported by a superstructure. The penetra- 
tion method has been used by Cameron and Gallagher, and by R. O. E. 
Davis for measuring coherence. The greater portion of their work is 
unconvincing because they failed to calculate the probable error of their 
determinations. Thaer and Engels have made penetration measurements 
in their work, but unfortunately the amounts of lime used were excessive. 

It would seem that penetration determinations should be made at a 
constant moisture content for essentially the same reasons as in the case 
of shrinkage. On bringing to air dryness, certain cementing materials 
undoubtedly come into play which are not operative under ordinary con- 
ditions. 

17. The Dynamometer Method consists in measuring the resistance 
offered to the passage of a plow through the soil. A spring is connected 



12 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

with a revolving drum in such a manner as to record the traction at any 
particular moment. We would expect that the summations of the values 
obtained from various lime plats, for instance, would indicate the effect 
of the lime on the physical condition of the soil. Work along this line 
has been undertaken by Mausberg and by Noll. Unfortunately the prob- 
able error involved is so high that experiments must be carried through a 
long series of years before significant results are obtainable. 

18. The Oxidative Power of the soil has never been used as a method 
for the estimation of internal surface. There seems no reason to doubt, 
however, that oxidation is in large part a surface phenomenon. The 
great ability of colloidal humus and hydrous ferric oxide to cause oxida- 
tion, as indicated by the work of Schreiner and his co-workers, would 
suggest that oxidation may be a specific and not a general phenomenon. 

Aloin is not suited for measurements of internal surface, owing to the 
fact that it is catalyzed by alkalies. An aloin solution will "keep" for 
only a few hours because of the presence of alkali dissolved from the con- 
tainer. An aloin solution will keep indefinitely if a small amount of 
acid is added when the solution is first made. The question arises in 
this connection whether Schreiner and Sullivan's study of the oxidizing 
power of soil extracts is particularly significant. 

Phenolphthalin is more satisfactory for estimating internal surface. It 
is convenient to read, and, unlike aloin, is very stable towards the atmos- 
phere. One precaution to be observed, is to avoid the use of a strong 
alkali in bringing out the full color of the phenolphthalein before reading. 
In a strongly alkaline solution the phenolphthalein is converted into the 
colorless leuco-base. Ammonia is a very satisfactory alkali to use in 
this connection. 

It is frequently desirable to clarify the solution with a precipitant, 
just prior to rendering the solution alkaline. If a soil has been rendered 
strongly basic by a salt treatment, the humus brought into suspension 
may modify the pink color to such a degree as to make a previous precipi- 
tation imperative. 

DISCUSSION 

In the preceding exposition we noted that the analogy between the 
suspension method and conditions as they actually exist in the soil, was 
not very close. There is no reason to doubt, however, that the funda- 
mental phenomena involved are essentially the same, the differences 
being simply a matter of degree. Cameron takes the point of view that 
there is no basis for attributing surface action to colloids, and Oedroits 
holds a similar opinion, on account of the small colloidal content of any 
soil. On taking into consideration the large internal surface involved 
on even a slight subdivision of any material, however, it is found nnneces- 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 13 

sary to stipulate any oilier action to account for the surface phenomena 
which take place. 

A consideration of the literature on the effect of lime sails on lloccula- 
tion reveals an unusual amount of confusion. The relation of valence to 
flocculating power has long been appreciated, but unfortunately invetiga- 
tors are just coming to realize that the question of active masses is of 
equal importance. For instance, sodium salts of weak acids are floccu- 
lents or defioeculents according to the relative concentrations of pre- 
cipitant and material being precipitated. This question has been dis- 
cussed in detail by Given, Wolkoff, and Wiegner. 

Rohland believes that on liming, the precipitating power is due to 
hydroxy] ions, and with calcium hydrate, the action is direct. With cases 
in which gypsum is applied, Rohland would assign the beneficial result to 
the precipitating power of the hydroxy 1 ions formed on the decomposi- 
tion of the salt. Here again, the various colloidal materials present in 
the soil tend to further confuse the phenomenon. Pappada finds that 
the hydroxyl ion is the most powerful in the precipitation of hydrous 
ferric oxide. Rohland's view would hold in so far as the positive colloids 
are concerned, but it would not hold for the negative. A soil suspension 
is usually negative, but there is no ground to believe that the colloidal 
material in the soil is entirely precipitated by cations or other bodies 
positively charged. 

Ehrenberg holds that the cation is the important flocculating agent. 
He ascribes a strong action to the calcium ion, and virtually none to the 
hvM-oxyl. Therefore calcium hydrate is the strongest flocculent of the 
lime salts. On increasing the strength of the acid in the salt, the pre- 
cipitating action becomes less and less, until in the case of gypsum, we 
have practically complete antagonism. Ehrenberg's theory is better than 
Rohland's just in so far as it better describes the actual state of affairs. 
As a matter of fact, both views are extreme. A solution of the question 
lies in the recognition of the complex nature of the colloidal material, 
and the fact that flocculation is a matter of relative charges, masses, 
and valencies. 

In past studies on the physical effect of lime on the soil, the tendency 
has been to make applications on a percentage basis. For example, a 
favorite custom has been to use (tut 1 per cent of lime, and there is one 
instance in the literature in which one part of lime was added to four 
parts of soil. In view of the relation of masses to precipitation, and 
furthermore, the wide departure from field practice involved, the question 
naturally arises whether the results from such experiments are particu- 
larly- significant. The work of Blanck, Thaer, and Engels, the lime 
studies most frequently quoted, are all open to the objection that the 
applications used were excessive. Unfortunately the methods available 
for physical studies have not been sufficiently accurate to be used in 



14 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 



work with comparatively small salt applications. In the present investi- 
gation, an attempt was made to obtain data from applications equal to 
and smaller than the lime requirement of the soil, in order to more nearly 
approximate field conditions. 



EXPERIMENTAL STUDIES 

All the soils used were of the Dunkirk silt loam series, and were 
obtained from two stations on the Cornell University farm. In addition, 
work was undertaken with samples from the lime plots on Caldwell Field. 
All the soils analyzed approximately the same merhanically. 

TABLE I. Mechanical Analysis of Dunkirk Silt Loam Soils 





Soil Tech. Plats 
and Station I 


Station II 


Total sands 


13.9' I 

67.4 

18.6 


9.8% 


Silt 


71.9 


Clav . 


18.3 







Unpublished results of bulk analyses give: 

TABLE II. Bulk Analyses of Dunkirk Silt Loaji Soil 
(From 9 samples of Tompkins County soil) 



• 


Surface % 


Subsoil % 


C. (organic carbon) 

CO.. 


1.670 

trace 

1.740 

0.430 

0.450 

1.090 

0.186 

. 123 


0.440 
0.260 


K 2 


2.110 


CaO 


0.830 


MgO 


0.690 


NaoO 


1.280 


N 


0.082 


P 2 5 


0.126 







In sampling the soil in the field, care was taken to get well down 
below the sod line in order that organic matter he excluded as far as 
possible. The material was brought in to the laboratory, put through a 
coarse sieve, and well mixed. The soil had an acidity of 3000 pounds of 
calcium oxide per acre, as determined by the Veitsch method. All the 
limes used were 200 mesh, and pots were set up with calcium hydrate, 
limestone, precipitated calcium carbonate, gypsum, and precipitated" cal- 
cium sulfate. In addition, studies were conducted with precipitated 
basic magnesium carbonate, and sodium carbonate. The limes were added 
in molecularly equivalent amounts, and proper collections were made 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 15 

for magnesium in the limestone (it was nearly pure), and for water of 
hydration. Applications were made in the equivalents of one-half, 
one and one-half, four and one-half, and ten tons of calcium oxide per 
acre, taking two and one-half million pounds as the weight of an acre — 
eight inches of soil. The one and one-half ton treatment exactly corre- 
sponded with the lime requirement of the soil. Into each pot was 
weighed the equivalent of 253 grams of oven soil. The container was 
given a prolonged tamping, two thicknesses of cotton gauze added, and 
finally a mulch of washed quartz sand placed on top to a thickness of one 
centimeter. Aerated distilled water was added to bring the pots up to 
24 or 28 per cent water content, at which they were maintained for the 
remainder of the experiment. ( Note : all references to water content 
in this treatise arc on an oven dry basis.) A portion of the series were 
set up in triplicate; the rest in quadruplicate. The duration of the 
experiments was 45, 100, and 225 days. On the expiration of the required 
time, the mulches were removed, the soil sieved (20 mesh I, dried down 
to 7-10 per cent, and bottled. The soils were never allowed to reach air 
dryness. 

In the exposition on procedures for estimating internal surface, 
eighteen methods were examined as to their respective merits. We found 
that the great majority are for one reason or the other inaccurate. Six 
of them were used in the present investigation, namely, — 

1 . Penetration. 

2. Expansion. 

3. Total retentive power. 

4. Dye adsorption. 

5. Hygro-interstitial water. 

6. Oxidative power. 

EFFECT OF SALTS ON PENETRATION 

The apparatus used for the measurement of penetrability was the 
Atterberg apparatus as improved by Prof. H. O. Buckman of Cornell 
University. The feature worthy of particular attention is the device for 
controlling the distance that the pin enters the soil. With the pin point 
flush with the surface of the soil, the mercury well may be set so that the 
metal point on top just makes contact with a similar point on the piston. 
The distance from this position to the surface of the mercury is constant, 
and represents the distance which the pin penetrates. Water is used to 
give the gradually increasing force to the head of the piston. On receiv- 
ing the signal from the sounder, the water is stopped, and the weight in 
the container is determined. This value represents the penetrability of 
the particular soil concerned. 

A series which had run for 100 days was used for the penetration 
determinations, and in order to avoid the results incidental to air drying, 



16 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 



readings were made when the moisture percentage of the soil was between 
14-15 per cent. Five readings were attempted in each pot, and since the 
series was in triplicate, fifteen readings per treatment were obtained. 

TABLE III. Penetration in Grams of Soils Limed for 100 Days 
(Each figure is the average of 15 determinations) 





( 'hecks 
(no ti\ at. ) 


Ga(0H) a 


Lime- 
stone 


pCaCOs 


Gypsum 


NaaCOs 


y 2 t 




1148 
115 
709 
196 
392 
29 
306 
15 


1716 

39 

1046 

37 

904 

27 

694 

34 




2157 
l. r 9 

1912 
182 

1832 
132 

173 7 
73 


4137 


P. E 






339 


m t 


2374 
152 

2294 
117 


4499 


P. E 




451 


4V 2 T 

P. E 

10 T 


787 
S3 


4678 

534 

3722 


P. E 






387 











While the probable error in some cases is rather high, nevertheless, 
we may draw the general conclusion that calcium hydrate decreases sur- 
face penetrability more than any of the other salts tried. One thing 
worthy of note is that calcium carbonate seemed to increase the value 
when used in small amounts. Unfortunately the question of crust forma- 
tion enters in, and tends to confuse the results. There is virtually no 
hardening on the surface of the untreated soil, while those to which has 
been added a half a ton of lime per acre may form quite a tough crust, 
as in the case of the gypsum treatments. What our results indicate, 
then, is that calcium hydrate causes the formation of a less impervious 
crust than any other lime. If the penetration method is to be used as a 
measure of the internal and not the surface condition, the crust must be 
removed. 

Penetration studies on the interior portion of the soil were attempted. 
Brass pins of various shapes and sizes were advanced into the soil with 
the ratchet of the micrometer used in connection with the expansion 
studies. The distance that the ratchet forced the pin into the soil was 
read directly on the micrometer scale. (The crust had been removed.) 
The results failed to show significant differences between the different 
salt treatments. We may therefore conclude that the influence of salt 
treatment is primarily on crust formation, in so far as the penetration 
method is a proper criterion. It cannot be used for very sensitive mens 
urements, because it is subject to a number of uncontrolled factors. 

EXPANSION STUDIES 

It was evident from the preliminary discussion that we would expect 
flocculation and expansion to go hand in hand. Furthermore, it seemed 
that expansion studies should be conducted at a constant moisture con- 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 



17 



tent. In order to observe expansions under these conditions, a series 
which was running for 100 days was selected for special experimenta- 
tion. Measurements were made according to a method suggested by 
Professor J. A. Bizzell of Cornell University. A ratchet micrometer was 
fastened to a standard so that the spindle head could play on a brass 
pin Avhich projected three-fourths of an inch above the surface of the 
soil. The pin passed perpendicularly through the middle of a small brass 
plate, the latter resting on the soil surface. The pin was further steadied 
by a projection passing down into the soil. A reading was made by 
lowering the micrometer spindle gently in to the pin, until there was 
a constant a pull" on the slip of thin paper inserted between pin and 
spindle. This method is accurate to the hundredth of a millimeter. 

In setting up the experiment, pins were placed on the one-half, one 
and one-half, and ten ton treatments only. The initial reading was 
made three hours after the pots had been brought up to weight. During 
the course of the experiment readings were taken from time to time; 
in each case, how r ever, 24 hours after watering, inasmuch as approxi- 
mately 24 hours were required to evaporate the water from the quartz 
mulch. 

Effect of Time and Salts on Soil Expansions 
(Each figure in the following data is the average of quadruulicate determinations. 

The values all have a negative sign, i. e., there was contraction in every case. 

Readings are in mm.) 



Treatment 


14 Days 


25 Days 


35 Days 


45 Days 


90 Day< 


No. treatment 

P. E 


1.76 

.18 

1.49 
.20 
.88 
.12 
.34 
.03 

1.20 
.18 

1.61 
.13 
. 55 
.08 

.98 
.15 
.86 
.07 
.90 
.04 

.57 
.12 


2.14 

.27 

1.85 
.09 

1.31 
.17 
.58 
.02 

1.56 
.18 

1.95 
.13 
.70 
.10 

1.50 

.23 

1.35 


2.44 

.25 

2.19 
.07 

1.59 
.21 
.79 
.03 

1.76 
.15 

2.35 
.14 

1.03 
.09 

1.84 

.27 

1.76 


3.31 
.26 

2.76 
.09 

2.17 
.14 

1.22 
.02 

2.31 
.18 

2.86 
.15 

1.49 
.10 

2.44 

.30 

2.33 


3.33 
.34 


Ca(OH) 2 

V 2 T 


3.31 


1KT . 


.08 
2.60 


10 T 


.18 
1.39 


Limestone 

Yi T 

\y 2 t 


.03 

2.68 

.32 

3.21 


10 T . 


.15 
1.72 


p. CaOOs 

i.,T 


.13 
2.96 


iy 2 t 


.49 
3.03 


10 T 


1.46 
.08 

1.03 
.14 


1.74 
.04 

1.21 
.12 


2.31 
.04 

1.67 
.12 


3.03 


p. CaS0 4 

y 2 t 


.07 
1.97 




.18 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 
Effect of Time and Salts on Soil Expansions — Continued 



Treatment 


14 Da^ s 


25 Days 


35 Days 


45 Days 


90 Days 


1 y 2 T 


.71 

.11 
.77 
.04 

.92 

.08 
1.28 

.19 
1.73 

.18 


1.33 
.15 

1.06 
.04 

1.49 
.15 

2.11 
,17 

2.05 
.29 


1.55 
.15 

1.22 
.04 

1.86 
.16 

2.46 
.18 

2.26 
.25 


1.89 
.06 

1.73 
.06 

.89 
.13 
.89 
.44 
3.24 
.60 


2.20 


10 T 


.09 
1.87 


p. MgCOs (basic) 
HT 


.08 
2.95 


IK2T 


.18 
3.47 


10 T 


.25 
3.71 


Na 2 CO :! 

V 2 T 


.44 
1.19 


iy 2 T 








.25 

2.02 


10 T 








.51 
3.83 










.67 



We see from the above data that the contraction with the calcium 
hydrate treatments is decidely less than with the limestone. There is not 
much difference between the limestone and precipitated carbonate data 
when small applications were employed. The limestone seemed to be 
superior to the precipitated carbonate, however, when large applications 
were used. There was less contraction with the soils to which precipitated 
calcium sulfate had been added than with any of the others. In this 
connection it should be noted that a smaller contraction than the check 
does not necessarily imply a greater expansion. Anything causing an 
abnormal solidification of the soil mass may be wrongly interpreted as 
an expansion. In the case of the sodium carbonate pots we probably 
have this action. The precipitated magnesium carbonate seems to exert 
no particularly striking effect. 



EFFECT OF LIMING ON THE TOTAL RETENTIVE POWER 

The determinations were carried out in the following manner: A soil 
of known moisture content was poured into a weighed Hilgard cup, in the 
bottom of which was a filter paper. After tamping a definite number of 
limes the top portion was struck off Avith a straight-edge, and then the 
cup and soil weighed. Knowing the moisture content of the soil, the 
dry weight equivalent in the cup could be easily determined. The cup 
was then set into water in a thermostat so that there would just be 
capillary contact. After the soils had become thoroughly saturated (a 
matter of several hours), the cups were set aside to drain, after which 
they were wiped dry, and weighed. A calculation of the amount of 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 



19 



capillary water taken up by the soil, based on the oven dry weight, was 
then made. 

Below are tabulated the results with treatments which had run for 100 
and 225 days, respectively. Each figure in the following tables is an 
average of six or eight determinations. 

Retentive Power of Soils Limed 100 Days: Series I 



Treatment 


Ca(OH) 2 


Lime- 
stone 


p.CaCOs 


Gypsum 


Na 2 C0 3 


Checks 


y 2 T 


49.1 

1.6 
50.5 

1.2 
49.0 

1.7 
49.2 

1.6 


50.1 

1.1 
51.5 

1.1 
51.0 

1.2 
49.3 

2.0 


51.6 
.9 

52.0 
.9 

51.6 
.9 

50.9 
1.3 


52.8 

.6 

53.4 

1.2 

56.2 

1.1 

54.3 

.8 


52.2 

1.6 

47.6 

.6 
44.5 

.5 
48.2 

.8 




P. E 




l^T... 




P. E. . 




4}/,T 

P. E 

10 T 


50.3 
1.1 


P. E. 









Retentive Power of Soils Limed 100 Days: Series II 



Treatment 


HT. 


IH T. 


10 T. 


Checks 


Ca(OH) 2 

P. E 


57.1 

1.0 

59.3 

.8 

56.2 

2.34 

54.7 

3.5 

49.6 

.6 

54.6 

.9 


55.3 

1.0 

56.9 

.9 

57.9 

1.6 
57.6 

1.4 

47.1 

.7 

54.4 

1.8 


56.5 

.5 
59.3 

.3 

55.3 

1.9 

54.4 

1.1 

48.0 

.4 
58.7 

.8 






p. CaC0 3 

P. E 






Limestone 


56.8 


P. E. . 


.3 


p. CaS0 4 . 




P. E 




Na>C0 3 . 




P. E. . . . . 




M. MgC0 3 .. 




P. E. . . 









Retentive Power of Soils Limed 225 Days: Series I 



Treatment 


Ca(OH) 2 


Lime- 
stone 


p. CaCOs 


Gypsum 


Na 2 C0 3 


Checks 


y 2 t 


51.3 

.6 
52.1 

.5 
50.8 

.5 
51.0 

.8 


48.3 
1.0 

50.2 
1.6 

52.0 
1.2 

49.4 
.2 


51.9 

.4 
55 . 1 

.6 
56.2 

.3 
54.0 

.1 


54.1 
1.3 

52.8 

.5 

52.2 

2.3 
50.6 

1.2 


51.0 
1.5 

46.7 
1.5 

47.2 
1.2 

50.2 
.1 




P. E 




l^T 

P. E 

4^T 


53.1 

.4 


P. E 




10 T 




P. E 









20 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

It may be readily observed that none of the salts affected the total 
retentive power in the case of the salts run 100 days, with the exception 
of the sodium carbonate. With the 225 day treatment, however, we find 
that both calcium hydrate and limestone have caused a slight decrease 
in water holding capacity. The precipitated carbonate may act in just 
the opposite direction. The gypsum is without effect. 

DYE ADSORPTION STUDIES 

In the preliminary discussion, attention was called to the fact that 
certain factors affecting dye adsorption have been entirely overlooked 
in studies with soils. Perhaps the most important of these factors are, 
the stability of the dye, and the effect of salts on the adsorption equilib- 
rium. There are, however, several other questions that arise in this 
connection : 

What is the influence of the time of shaking on the adsorption equilib- 
rium, and 

Does the mechanical agitation incidental to shaking tend to destroy the 
flocculated condition, and hence affect the degree of adsorption? 

In order to study the effect of time of shaking, adsorptions were run 
and terminated at regular intervals. Using two grams of Dunkirk silt 
loam in methylene blue, it was found that complete equilibrium was 
reached in from one to two hours. 

The effect of mechanical agitation on adsorption was studied by 
adding two grams of soil to solutions in shaker bottles, the latter con- 
taining the amount of salt that would be carried over in a two gram 
charge of soil treated at the rate of 10 tons per acre. After shaking two 
hours, a feAV cc. of a concentrated methylene blue solution was added, 
and the shaking continued for five minutes longer. The results showed 
that final equilibrium had not been affected by the salts present, with 
the exception of the sodium and magnesium carbonate treatments, and 
in these cases we do not have to postulate any change in stability of the 
colloidal material, inasmuch as the solutions were very alkaline, and 
hence could affect the adsorption equilibrium. The subject was studied 
still further by running adsorptions in methylene blue, and determining 
whether the final result was the same irrespective of the salt present. 
Here again, the sodium and magnesium carbonates were found to increase 
adsorption somewhat. 

Adsorption experiments with methylene blue were run as follows: 
The equivalent of 2 grams of oven soil was weighed into the shaker 
bottle containing 100 cc. of the dye (.25 gram per litre). After shaking 
two hours, the clear supernatant solution was read against a standard. 
The results with soils which had been limed for 100 and 225 days are 
as follows: 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 



21 



Adsorption of Methylene Blue by Soils Treated for 100 Days 
(Readings in divisions equivalent to 100 of standard) 



Treatment 


Ca(OH) a 


Lime- 
stone 


p. CaCOa 


Gypsum 


Checks 




272 

208 

153 

70 


217 
190 
163 
143 


144 
159 
112 
100 


180 
153 
118 
110 




y T . 




1 V-) T 


235 






\y 2 t 




10 T 









Adsorption of Methylene Blue by Soils Treated for 225 Days 



Treatment 



4V 2 T 
10 T. 



Ca(OH) 2 



183 
162 
117 

57 



Lime- 
stone 



210 
151 
138 
139 



p. CaC0 3 



168 
163 
140 
133 



Gypsum 



114 

95 

106 

82 



Each figure in the preceding tables is the average of triplicate deter- 
minations. While calcium hydrate decreases adsorption the most when 
10 ton treatments are used, precipitated carbonate and gypsum are more 
efficient with slight applications. 

Studies were conducted with safranine in order to observe the effect 
of salts in the adsorptive power of the organic matter. Preliminary 
experiments indicated that adsorptions could not be conducted with 
safranine in the presence of sodium and magnesium carbonates. The 
results are as follows : 

Adsorption of Safranine by Soils Treated for 45 Days 



Treatment 


Check 


Ca(OH) 2 


Lime- 
stone 


p. CaCOs 


Gypsum 


1 14 T 


51 


52 
44 


52 
45 


62 
42 


60 


10 T 


62 








Adsorption of Safranine by Soils Treated for 225 Days 



Treatment 



1HT. 
10 T.. 



Check 



51 



Ca(OH) 2 



47 

42 



Lime- 
stone 



60 
61 



p. CaC0 3 



61 
61 



Gypsum 



34 
34 



22 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 



With the soils treated for 45 days, liming seemed to decrease the 
adsorptive power when applied in excessive amounts. The same applies 
to calcium hydrate and gypsum for the 225 day treatments. On the 
other hand, limestone and precipitated carbonate increased the adsorp- 
tive power slightly. It may be that the analogy of internal surface does 
not apply to organic matter, and that the influence of salts on the 
adsorptive power is primarily chemical rather than physical. 

Adsorption experiments were conducted with diamine sky blue and 
with diamine violet, both of which are specific for hydrous aluminum 
oxide. Unfortunately neither is stable in the presence of very much elec- 
trolyte, and experiments could be conducted with soils which had been 
limed not to exceed a ton and a half per acre. The tests failed to show 
any differences in adsorptive power. In other words, limes do not 
precipitate hydrous aluminum oxide when added in the equivalent of a 
ton and a half per acre. The writer has found eosin to be much better 
than either of the above dyes for the study of the adsorptive power of 
aluminum. Its adsorptive equilibrium is not influenced by salts present 
in solution in the equivalent of 10 tons per acre. 



Adsorption of Eosin by Soils Treated for 45 Days 



Treatment 


Ca(OH) 2 


L. S. 


p. CaC0 3 


Gypsum 


Na 2 00 3 


Checks 


1 V, T 

10 T 


56 
45 


58 
45 


51 
40 


45 

41 


54 

48 


54 







Absorption of Eosin by Soils Treated for 225 Days 



Treatment 


Ca(OH) 2 


L. S. 


p. CaC0 3 


Gypsum 


Na 2 COs 


Checks 


1MT 

10 T 


26 
24 


25 
24 


24 
24 


25 
25 


22 
23 


30 







It seems from the above data that all limes precipitate aluminum to 
some degree. Probably gypsum has a stronger action in this respect 
than any of the others. 

Taking the adsorption data as a whole, it appears that the primary 
effect of liming is the precipitation of the silicic acid, as indicated by the 
methylene blue tests. The influence of lime is noticeable, even when 
added in very small amounts. Indirectly, we also get a precipitation 
of the aluminum, and perhaps the organic matter. Any statement as to 
the effect on the colloidal iron will have to be deferred until a suitable 
dye is obtained. 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 



23 



HYGRO INTERSTITIAL MOISTURE STUDIES 

In view of the unsatisfactory results obtained by the Rodewald-Mit- 
scherlich method, it seemed desirable to revert to the type of procedure 
used in the beginning. The writer has been fortunate in obtaining a 
method which is free from errors due to condensation, and is at the same 
time exceedingly accurate. Preliminary work with this method indicates 
that liming seems to have no significant effect on hygro-interstitial mois- 
ture in amounts equivalent to the lime requirements of the soil. Exces- 
sive applications decrease the value. 

OXIDATION STUDIES. 

The work was conducted as follows: The equivalents of four grams of 
soil were weighed into S-oz. bottles, and 50 cc. of phenolphthalein solu- 
tion added. After oxidation had progressed satisfactorily, the solutions 
were cleared of humus and suspended matter with hot alum solution, an 
aliquot made alkaline with ammonia, and read against a standard. The 
results are as follows: (Each figure is the average of three determina- 
tions. The probable error is approximately a plus or minus two). 



Oxidation of Phexolphthaleix by Soils Treated for 100 Days 



Treatment 


Cheek 


Ca(OH): 


L. S. 


p.CaCOs 


p. CaSO, 


Na 2 C0 3 


). MgCOs 


4 T 

1^ T 


75 


97 

88 

1C4 


87 
72 
63 


100 
98 
71 


76 
58 

50 


95 
95 
86 


82 
71 


10 T. 




47 









OXIDATIOX OF PHEXOLPHTHALEIX BY SOILS TREATED FOR 225 DATS 



Treatment 


Checks 


Ca(OH) 2 


L. S. 


p. CaC0 3 


Gypsum 


Na 2 CO, 


\ , T 




71 

82 

88 


62 
72 
75 


63 
72 

73 


46 
45 
57 


61 


P , T 

10 T 


76 


53 
52 









The data for the soil run 225 days goes just about as we would like it 
to go. ^Ye get the greater oxidation in soils in which we would expect 
the greater internal surface, and we obtain a decrease in oxidation with 
increasing applications of lime. The results for the soils run 100 days 
are not quite so satisfactory. It may be that in certain cases an exchange 
of bases results in the release of substances which catalyze the reaction. 



24 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

STUDIES WITH PLAT SOILS 

An attempt was made to determine whether differences could be 
observed between soils from limed and unlimed plats, using our methods 
for estimating internal surface. Accurate samples of the surface and 
subsoil were taken from plats 7007, 7008, 7207, 7208, 3611, 3612, 3613, 
and 3614. The seven thousand plats received a moderate application of 
CaO in the summer of 1915, while the three thousand plats were last 
limed in the summer of 1910. The soils were examined according to the 
total retentive power, dye adsorption, and oxidation methods. None of 
the results were consistent with regard to the limed and unlimed plats, — 
with one exception, — the oxidation results for the seven thousand plats. 

Oxidation of Phenolphthalein by Lime Plat Soils 



Soil 


Description 


Comparative Figure 


7007 

7008 


Unlimed 

I itnod 


£9.5 

63 


7207 

720S 


Unlimed 

Limed 


93.0 
106.0 







The above figures are averages of duplicate determinations, and the 
probable error is less than one. We may conclude that several years time 
are usually sufficient to virtually obliterate all physical differences 
between limed and unlimed soils. 

DISCUSSION 

Six methods have been employed in the present investigation. We 
have observed that the total retentive power and penetration procedures 
are not particularly valuable because of the high probable error involved. 
The oxidation method has not been used sufficiently as a means of esti- 
mating internal surface to permit its appraisement at the present time. 
Expansion, hygro-interstitial moisture, and dye adsorption seem to be 
accurate and valuable methods. It appears to the writer that the dye 
method has the brightest future of all, for it permits the determination 
of tiic effect of substances in specific materials. 

CONCLUSIONS 

1. The penetration method is not a suitable procedure for estimating 
internal surface. 

2. Small contraction exhibited by a salt treated soil does not neces- 
sarily imply large expansion. 

3. Gypsum treated soils contracted less than any other lime treat- 
ment. 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 2 5 

4. Gypsum appears to be an active precipitant of silicic acid and 
hydrous aluminum oxide. 

5. New methods for the determination of soil expansions and hygro- 
interstitial water have been devised. 

6. Liming in amounts equivalent to the lime requirement of the soil 
has no effect on the hygro-interstitial water. 

7. Calcium hydrate is only slightly more valuable as an ameliorating 
agent than limestone. 

8. The physical effect of precipitated magnesium carbonate on the 
soil is nil. 

9. The dye adsorption method has the greatest possibilities of all 
methods for estimating internal surface. 

10. The primary effect of liming is on the silicic acid. 

BIBLIOGRAPHY 

1. Adams, E. A., and Rosenstein, L. 

1914. The Color and Ionization of Crystal Violet. 
J. Am. Chem. Soc. 36, 1452. 

2. Albert, R. 

1905. Welche Erfahrungen liegen bis jetzt tiber den Einflusz 
kunstlicher Diingung und Bodenbearbeitung im forst- 
lichen Groszbetreitie vor? In welcher Weise und nach 
welcher Richtung hin sind Versuche hieruber fernerhin 
anzustellen ? Zeitschr. f. Forst. und Jagdwesen, 37, 139. 

3. Ames, J. W., and Schollenberger. C. J. 

1916. Liming and lime requirement of soil. Obio Expt. Sta. 
Bui. 306. 

4. Ammon, G. 

1879. Untersuchungen fiber das Condensationsvermogen der 
Bodenconstituenten fiir Gase. 
Forsch. a. d. Gebiete der Agrikultur-Physik, 2, 1-40. 

5. Arntz, E. ' 

1909. Tonbestimmung im Boden. 
Landw. Versuchss., 70, 269. 

6. Ashley, H. E. 

1909. The colloidal matter of clay and its measurement. U. S. 
Geol. Survey Bui. ass. 

7. Ashley. H. E. 

1913. Technical control of the colloidal matter of clays. Bureau 
of Standards Technologic Paper No. 23. 

8. Atterberg, A. 

1911. Die Plastizitat der Ton. 

Internat. Mitt. f. Bodenkunde. 1, 10. 



26 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

9. Atterberg, A. 

1912. Die Konsistenz und die Bindigkeit der Boden. 
Internal. Mitt. f. Bodenknnde, 2, 149. 

10. Atterberg, A. 

1914. Die Konsistenz Kurven der Mineralboden. 
Internat. Mitt. f. Bodenknnde, 4, 418. 

11. Bancroft, W. D. 

1914. The theory of colloid chemistry. 
Jour. phys. chem. 18, 549. 

12. Bancroft, W. D. 

1914-15. The Theory of Dyeing. 

Jour. phys. chem. 18, 1, 118. and 385. 19, 50, and 145. 

13. Bancroft, W. D. 

1915. Hydrous ferric oxide. 
Jour. phys. chem. 19, 232. 

14. Barus, C. 

1886. Uber das Absetzen von feinen festen Massenteilchen in 
Fltissigkeiten. 
Ann. Phys. V. Chem. 12, 503. 

15. Beaumont, A. B. 

1918. The Keversibility of Soil Colloids. 
Thesis, Cornell University. 

16. Bechhold, H. 

1912. Die Kolloide in Biologic und Medizin. Dresden. 

17. Bemmelen, J. M. van. 

1S7S-7!). Das Absorptionsvermogen der Ackererde. 
Landw. Versuchss. 22, 135, 205. 

18. BlOM.MKLEX, J. M. VAX. 

1881. Die Verbindungen einiger fester Dioxydhydrate mit 
Sauren, Salzen, und Alkalien. 
Jour, prakt. Chem., (Ser. 2) 23, 388. 
1!). Bemmelen, J. M. vax. 

1888. Die Absorptionsverbinduugen und das Absorptionsver- 
mogen der Ackererde. 
Landw. Versuchss. 35, 69. 

20. Bemmelen, J. M. vax. 

1904. Beitriige zur Kenntnis der Verwitterungsprodukte der 
Silikate in Ton. vulkanischen und Lateritboden. 
Zeit. f. anorg. Ohemie, 42, 205. 

21. Bemmelen, J. M. vax. 

1909. Die Verwitterung von Tonbbden. 
Zeit. f. anorg. Chem. 62, 221. 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 2 7 

22. Bemmelen, J. M. van. 

1910. Die verschiedenen Arten der Yerwitterung der Silikat- 
gesteine in der Erdrinde. 
Zeit. f. anorg. Chemie, 66, 322. 

23. Bemmelen. J. M. von. 

1910. Die Absorption : gesammelte Abhandlung iiber Kolloide 
und Absorption; mit unterstiitzung des Verfassers neu 
herausgegeben von W. Ostwald. Dresden. 

24. Blanck, E. 

1909. Der Einfluss des Kalkes auf die Wasserbewegungen im 
Boden. Landw. Jahrb. 38, 715. 

25. Blanck, E. 

1909. Ein Beitrag zur Kenntnis der Wirkung ktinstlicher 
Diinger auf die Durchlassigkeit des Bodens fur Wasser. 
Landw. Jahrb. 38, 863. 

26. Blanck:, E., und Dobrescu, J. M. 

1914. Weitere Beitriige zur Beschaffenheit rotgefarbter Boden- 
arten. Landw. Versuchss. 84, 427. 

27. BODLANDER, G. 

1893. Versuche iiber Suspensionen. 
Jahrb. f. Min. 11, 147. 

28. Brehm, H. 

1913. Uber die Fortsehritte und Aussichten der jimgereu Agri- 
kulturchemie (speziell der Bodenchemie) seit Anwendung 
der neueren Ergebnisse der physikalischen Chemie, b'e- 
sonders der Kolloidchemie. Kolloid Zeit. 13, 19. 

29. Briggs, L. J., and McLane, J. W. 

1907. The moisture equivalents of soils. 
U. S. Bureau of Soils, Bui. 15. 

30. Brown, G. H., and Montgomery, E. T. 

1913. Dehydration of Clays. 

U. S. Bureau of Standards, Technologic Paper No. 21. 

31. Buhler, A. 

1892. Untersuchungen iiber Sickerwassermengen. Mitt. d. 
Schweiz. Zentralanstalt fiir forstl. Versuchswesen 1, 
291. Cited from Jahresb. Agr.-Chem. neue. Folge, 15, 
(1892), 97. 

32. Cameron, F. K. 

1915. Soil colloids and the soil solution. 
Jour. phys. chem. 19, 1. 

33. Cameron, F. K., and Gallagher, F. E. 

1908. Moisture content and physical condition of soils. 
U. S. Bureau of Soils, Bui. 50. 



28 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

34. Cornu, F. 

1909. Die Anwendung der histologischen Methodik zur mikro- 
skopischen Bestimmnng von Kolloiden, namentlich in der 
Bodenkunde. Koll. Zeit. 4, 304. 

35. CzERMAK, W. 

1912. Ein Beitrag zur Erkenntnis der Veriinderungen der sog. 
physikalischen Bodeneigenschaften durch Frost, Hitze, 
und die Beigabe einiger Salze. Landw. Versuchss. 76, 
73. 

36. Davis, R. O. E. 

1912. The effect of soluble salts on the physical properties of 
soils. U. S. Bureau of Soils, Bui. 82. 

37. Dittler, E. 

1909. Ueber die Einwirkung organischer Farbstoffe auf Miner- 
algele. Koll. Zeit. 5, 93. 

38. Dobeneck, A. F. VON. 

1892. I. Physik des Bodens. LXV. Untersuchungen iiber das 
Adsorptionsverinogen und die Hygroskopizitat der 
Bodenkonstituenten. Forsch. a. d. Gebiete d. Agrikultur- 
Pkysik, 15, 163. 

39. Ebermeyer, E. 

1890. Untersuchungen iiber die Sickerwassermengen in verschi- 
edenen Bodenarten. Forsch. a. d. Geb. d. Agrikultur- 
Physik. 13, I. 

40. Ehrenberg, P. 

1908. Theoretische Betrachtungen iiber die Beeinflussung 
einiger der sogenannten physikalischen Bodeneigenschaf- 
ten. Mitt, d. Landw. Inst. d. Fniver. Breslau, 4, 445. 

41. Ehrenberg, P. 

1915. Die Bodenkolloide. Verlag von T. Steinkopf, Dresden 
und Leipzig. 

42. Ehrenberger, P., und Pick_, H. 

1911. Beitrag zur Physikalischen Bodenuntersuchungen. 
Zeit. f. Forst. und Jagdwesen, 43, 35. 

43. Engels, O. 

1914. Der Einfluss von Kalk in Form von Atzkalk und kohlen- 
saurem Kalk auf die physikalische Beschaffenheit ver- 
schiedener Bodenarten. Landw. Versuchss., 83, 409. 

44. Fickendey, E. und Tollens, B. 

1906. Notiz iiber Schutzwirkung von Kolloiden auf Tonsuspen- 
sionen und naturlische Tonboden. Jour. f. Landw. 54, 
343. 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 29 

45. Fippin, E. O. 

1910. Some causes of soil granulation. Proc. Am. Soc. Agron. 
2, 106. 

46. Fraps, G. S. 

1914. Ammonia soluble inorganic soil colloids. 
Tex. Sta. Bui. 165, 3. 

47. Frear, W. 

1900. The agricultural use of lime. 

Commonwealth of Pennsylvania, Bui. 61. 

48. Frear, W. 

1915. Sour soils and liming. 
Pennsylvania Dept. or Agr., Bui. 61, 

49. Free, E. E. 

1900. The phenomenon of flocculation and deflocculation. 
•Jour. Franklin Inst. 169, 421. 

50. Freundlich, H. 

1909. Kapillarehemie ; eine Darstellung der Chemie der Kolloide 
und verwandter Gebiete. Leipzig. 

51. (Jans, K. 

1913 14. Uber die ehemische oder physikalische Natur der Kol- 
loiden Tonerdesilikate. Zentralb. f. Min. u. Geol. 1913, 
699, 728. 1914, 273, 299, und 365. 

52. Gedroits, K. K. 

1912. (Russian title). Colloid chemistry in the study of soils. 
Zhur. Opytn. Agron. (Knss. Jour. Expt. Landw.), 13, 
363. 

53. Gile, P. L. 

1911. Relation of calcareous soils to pineapple chlorosis. Porto 
Rico Agr. Expt. Sta., Bull. 11, 45. 

54. Gile, P. L.. and Carrero, J. O. 

1914. Assimilation of colloidal iron by rice. 

U. S. Dept. Agr., Jour. Agr. Research, 3, 205. 

55. Given, G. 

1915. Kolloide Eigenschaften des Tons und ihre Beeinflussung 
(lurch Kalksalze. Inaug. Dissert. Gottingen. Cited 
from Koll. Zeit., 81, 29. • 

56. Gross, E. 

1903. Uber den Einfluss der kiinstlichen Diingemittel auf das 
Verhalten des Wassers im Boden. Zeit. f. d. Landw. 
Versuchswesen in Osterreich, 6, 80. 

57. Haberlandt, H. 

1878. Uber die Koharescenz Verhaltnisse verchiedener Boden- 
arten. Forsch. a. d. Geb. d. Agrikultur-Physik, 1, 148. 



30 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

58. Hall, A. D. 

1908. The Soil. London. 

59. Hardy, W. B. 

1899. A preliminary investigation of the conditions which de- 
termine the stability of irreversible hydrosols. Proc. Roy. 
Soc. London. 66, 110. 

GO. Heiden, E. 

1883. Kondensation des Wasserdampfes durch lufttrockenen 
Boden. Denkschrift zur Feier des 25 jahriger Bestehens 
der agrikulturchemischen Versuchsstation Pommritz. 
Hannover. Forschnngen a. b. Gebiete d. Agrikultur- 
Physik, 7, 324. 

61. Hilgard, E. H. 

1911. Soils. New York. p. 209. 

62. Hollemann, A. F. 

1892. Uber die Bekalknng von steifen Kleyboden. 
Landw. Versuchss. 41, 37. 

63. HlJNDESHAGEN, F. 

1908. Ueber die Anwendung organischer Farbstoffe zur diag- 
nostischen Farbung mineralischer Substrate. 
Zeit. f. angew. Chem. 21, 2405. 

64. Immendorff, H. 

1913. Die an hydratischer Kieselsaure reichen Kalke als 
Dungemittel. Landw. Versuchss. 79-80, 891. 

65. Keppler, G., und Spangenberg, A. 

1907. Notiz uber die Schutzwirkung von Kolloiden auf Tonsus- 
pensionen. Jour. Landw. 55, 299. 

66. Kinnison, C. S. 

1915. A study of the Atterberg plasticity method. U. S. Bureau 
of Standards. Technologic Paper No. 46. 

67. Konig, J., Hasenbaumer, J., und Hassler, C. 

1911. Bestimmung der Kolloide im Ackerboden. 
Ladw. Versuchss. 75, 377. 

68. Krawkow, S. 

1900. Uber die Prozesse der Bewegung des Wassers und der 
Salzlosungen im Boden. Jour. f. Landw. 48, 209. 

69. Lacroix, A. 

1914. Les produits d'alteration des roches silicate'es alumi- 
neuses, et en particulier les laterites de Madagascar. 
Compt. Rend. Acad. Sci. (Paris), 159, 617. 

70. Lehmann, O. 

1894. Ueber Sedimentation und Farbstoffabsorption. 
Zeit. Phys. Chem. 14, 157. 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 31 

71. MacIntire, W. H. 

1916. Factors influencing the lime and magnesia requirements 
of soils. Tenn. Agr. Expt. Sta. Bui. 115. 

72. MacIntire, W. H. 

1916. The carbonation of burnt lime in soils. Thesis, Cornell 
University. 

73. MacIntire, W. H., Willis, L. G., and Holding, W. A. 

1914. The Non-Existence of Magnesium Carbonate in Humid 
Soils. Tenn. Agr. Expt. Sta. Bui. 107, 151. 

74. MacIntire, W. H., and Willis, L. G. 

1914. Comparison of silicates and carbonates as sources of lime 
and magnesia for plants. Jour. Indus, and Engin. Chem. 
6, 1005. 

75. Maschhaupt, J. G. 

1914. Einige Bemerkungen zu Trof. Dr. Rohlands : Die Wir- 
kung der Hydroxylionen auf Tone imd tonige Boden bei 
der Mergelung. Landw. Versuchss. 83, 467. 

76. Masoni, G. 

1912. Intorno all'azione flocculante di alcuni sali solubili sulle 
materie argillose del terreno. Staz. Sper. Agri. Ital., 45, 
113. 

77. Mausberg, A. 

1913. Wie beeinflusst die Dtingung die Beschaffenheit des 
Bodens und seine Eignung fiir bestimmte Kulturgew- 
achse? Landw. Jahrb. 45, 51. 

78. Mayer, A. 

1879. Ueber die Einwirkung von Salzlosungen auf die Abset- 
zungsverhaltnisse thoniger Erden. Forsch. a. d. Geb. d. 
Agrikultur-Physik, 2, 251. 

79. McGeorge, W. T. 

1915. Soil Colloids. 

Hawaii Agr. Expt. Sta. Report 1915, 36. 

80. Meyer, A. 

1874. Uber das Verhalten erdartiger Gemisehe gegen das 
Wasser. Landw. Jahrb. 3, 794. 

81. Mitscherlich, E. A. 

1898. Beurteilung der physikalischen Eigenschaften des Acker- 
bodens mit Hilfe seiner Benetzungswarme. Inaug. Dis- 
sert. Kiel. 

82. MlTSCHERLICH, E. A. 

1905. Die Bodenkunde. Berlin. 



32 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

83. Noll, C. F. 

1913-14. Effect of fertilizers on soil structure as indicated by the 
draft of a plow. Penn. Agr. Expt. Sta. Annual Report, 
p. 36. 

84. Oryng, T. 

1914. Kritische Bemerkungen zur Frage der Bestimmung des 
Adsorptionsvermogens des Bodens. Koll. Zeit 15, 10."). 

85. OSTWALD, W. 

1910. Grundriss der Kolloidchemie. Dresden. 

86. Pappada, X. 

1911. Uber die Koagulation des Eisenhydroxyds. Koll. Zeit. 
9, 233. 

87. Parker, E. G. 

1914. Selective adsorption. 

Jour. Ind. Eng. Chem. 6, 831. 

88. Pelet-Jolivet, L. 

1910. Die Theorie des Farbeprozesses. Dresden. 

89. Pelet-Jolivet, L. 

1909. Ueber die Adsorptionsverbindungen. Koll. Zeit. 5, 85. 

90. Pelet, L. und Andersen, N. 

1908. Ueber den Einflusz von Sauren und Basen auf den 
Fiirbungsvorgang. Koll. Zeit. 2, 225. 

91. Pelet, L. und Grand, L. 

1907. Ueber die Bindung einiger Farbstoffe durcb unlosliche 
Mineralsubstanzen. Koll. Zeit. 5, 94. 

92. Pelet, L. und Grand, L. 

1907. Ueber den Einflusz von Salzen auf den Farbungsvorgang. 
Koll. Zeit. 2, 83. 

93. PlCTON, H. AND Linder, S. E. 

1892 & Solution and pseudo-solution. 
1895. Jour. Chem. Soc. 61, 148, and 67, 63. 

94. PlTCHNER, H. 

1889. Untersuchungen iiber die Kohareszenz der Bodenarten. 
Forsch. a. d. Geb. d. Agrikultur-Physik. 12, 195. 
9.". Puchner, H. 

1913. Vergleicbende Untersuchungen iiber die Kohareszenz 
verschiedener Bodenarten. Internat. Mitt. f. Bodenk. 3, 
141. 

96. Bodewald, H., und Mitscherlich, E. A. 

1903. Die Bestimmung der Hygroskopizitat. 
Landw. Versuchss. 59, 433. 

97. Rogers. A. F. 

1917. A review of the amorphous minerals. 
The Jour, of Geology, 25, 515. 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

98. ROHLAND, P. 

1910. Die Kolloidstoffe in den Tonen und die Adsorptions- 
phanomene. Landw. Jahrb. 39, 369. 

99. Kohland, P. 

1914. Die Wirkung von Alkalisilikaten auf Ton und Kaolin 
suspensionen. Koll. Zeit. 15, 158. 

100. ROHLAND, P. 

1914. Die Wirkung der Hydroxylionen auf Tonige Boden. 
Landw. Versuchss. 85, 105. 

101. Kohland, P. 

1914. Die Adsorptionsfahigkeit des Kaolins. 
Koll. Zeit. 14, 193. 

102. Kohland, P. 

1914. Die Adsorptionsfahigkeit der Talke und Kaoline. Koll. 
Zeit. 15, ISO. 

103. Kohland, P. 

1915. Die Adsorption der Farbstoffe durch Kolloidton usw. 
Koll. Zeit. 16, 16. 

104. ROHLAND, P. 

1915. Die Adsorptionsfahigkeit des Torfmoors. 
Koll Zeit. 16, 146. 

105. RtJPRECHT, Fi. W., AND MORSE, F. W. 

1914. The effort of sulfate of ammonia on soil. 
Mass. Agr. Expt. Sta. Bui. 165, 76. 

106. Sachsse, Pi. und Becker. A. 

1894. Der Einfluss des Kalkes der Salze. sowie einiger Sauren 
auf die Flockung des Thones. Landw. Versuchss. 43, 15. 

107. SCHREINER, O., AND REED, H. J. 

1909. The role of oxidation in soil fertility. 
U. S. Bureau of Soils, Bui. 56. 

108. SCHREINER, O., AND SULLIVAN, M. X. 

1910. Studies in soil oxidation. 

U. S. Bureau of Soils, Bui. 73. 

109. SCHUBLER, G. 

1838. Grnndsiitze der Agrikultur-Chemie. 
Leipzig. II. Theil. 82, 95. 

110. SCHULZE, H. 

1882. Schwefelarsen in wassriger Losung. 

Jour. f. prakt. Chemie. Ser. 2, 25, 431. 

111. SCHWARZ, A. R. VON. 

1878. Erster Bericht iiber Arbeiten der K. K. landwirthschaft- 
lichen Versuchss. in Wien aus den Jahren, 1870-1877. 
Wien. Seite 51. 



34 THE PHYSICAL ACTION OF LIME ON CLAY SOILS 

112. Sharp, L. T. 

1915. Salts, soil colloids, and soils. 
Proc. Nat. Acad. Sci. 1, 563. 

113. Sharp, L. T. 

1916. Fundamental interrelationships between certain soluble 
salts and soil colloids. Univ. Cal. Publications in Agr. 
Sci. 1, 291. 

114. Sjollema, B. 

1905. Die Isolierung der Kolloidsubstanzen des Bodens. 
Jour. Landw. 53, 70. 

115. Sokolovskii, A. N. 

1914. (Russian title) . The sphere of adsorption phenomena in 
the soil. Zhur. Opytn. Agron. 
(Faiss. Jour. Expt. Landw.), 15, 67. 

116. Stevenson, E. F. 

1912. Ueber Schutzwirkung von Farbstoffen. 
Koll. Zeit. 10, 249. 

117. Strbmme, H., und Aarnio, B. 

1911. Die Bestimmung des Gehaltes anorganischer Kolloide in 
Zersetzten Gesteinen und deren Unlagerungsprodukten. 
Zeit. f. Prakt. Geol., 19, 329. 

118. Svedberg, Th. 

1909. Die Methoden zur Herstellung kolloider Losungen, anor- 
ganischer Stoffe; ein Handund Hilfsbuch fiir die Chemie 
und Industrie der Kolloide. Dresden. 
119. Tadokoro, T. 

1914. Uber die Kolloidalen Eigenschaften der Sauren Boden in 
Japan. Jour. Coll. of Agr., Tohoku Imp. Univ., 4, 27, 117. 

120. Taylor, W. W. 

1915. The chemistry of colloids. 
Longmans, Green and Co., New York. 

121. Tempany, H. A. 

1917. The shrinkage of soils. 
Jour. Agr. Sci., 8, 321. 

122. Thaer, W. 

1911. Der Einfluss von Kalk und Humus auf die Mechanische 
und Physikalische Beschaffenheit von Ton, Lehm, und 
Sandboden. Jour. f. Landw. 59, 9. 

123. Treutler, C. 

1871. Untersuchungen iiber die Wasserhaltende Kraft der 
Boden und Bodenbestandteile. 
Landw. Versuchss. 14, 301. 



THE PHYSICAL ACTION OF LIME ON CLAY SOILS 35 

124. Van der Leeden, R., und Schneider, F. 

1912. (German title). New methods of soil analysis and the 
estimation of colloids in soils. 
Interna. Mitt. f. Bodenk. 2, 81. 

125. Yoelcker, J. A. 

1909. Effect of colloidal substances on soil productivity. Jour. 
Roy. Soc, 70, 388. 

126. Vogel, A. 

1881. Untersuchungen iib'er die Sickerwasser einiger Bodenar- 
ten. Sitzber. d. K. b. Akad. d. Wissenschaften zu 
Miinchen 1881. 259. 

127. WlEGNER, G. 

1912. Zum Basenaustausch in der Ackererde. 
Jour. Landw. 60, 111. 

128. Wiegxer, G. 

1914. Uber die chemisehe oder physikalische Nature der kolloi- 
den, wasserkaltigen Tonerdsilikate. 
Zentralbl. f. Min. u. Geol. 1914, 262. 

129. Williams, W. R, 

1895. Uber die mechanische Bodenaiial.vse. 

Forseh. a. d. Ged. d. Agrikultur-Physik. 18, 257, 291. 

130. Wolff, E. 

1875. Anleitung zur chemischen Untersuchungen landw. wicli- 
tiger Stoffe. Berlin. 

131. WOLKOFF, M. I. 

1916. Studies in soil colloids. I. Flocculation of soil colloidal 
solutions. Soil Science. 1, 585. 

132. Wollny, E. 

1897-98. XCVII. Untersuchungen uber die Volumveranderungen 
der Bodenarten. Forseh. a. d. Geb. d. Agri.-Physik. 20, 1. 

133. Wollny, E. 

1898. Untersuchungen iiber die Feuchtigkeitsverhaltnisse der 
Bodenarten. Forseh, a. d. Geb. d. Agrik.-Physik. 20, 482. 

134. Zsigmondy, R. A. 

1912. Kolloidchemie. ein lehrbuch von Richard Zsigmondy. 
Leipzig. 



